Re: Paper on symmetry of XPath axes

Holger Meuss wrote:
> 
> On a syntactic level it is easy to see that e.g.
> 
> descendant::a/preceding-sibling::b[position()<=3]
> 
> is equivalent to
> 
> descendant::b[following-sibling::a][position()>last()-3].

Are you sure? Consider the document

   <foo>
      <b/>
      <b/>
      <b/>
      <a/>

      <b/>
      <b/>
      <b/>
      <a/>
   </foo>

I think the first expression selects all the <b/> elements, whereas the
second selects just the 4th through 6th.

-Michael Dyck